Sex differences in immune responsiveness of CFW mice to Candida albicans will be studied. The model system studied is the delayed skin test reactivity of mice to candida antigen injected intradermally. The influence of gonadal hormones on this response both actively induced with antigen or passively transferred with lymphoid cells will be studied. In addition the influence of gender and gonadal hormones on the skin test response to in vitro lymphocyte-produced mediators will be investigated.